Thanks for the input, everyone. I suppose what I'll be trying is to go straight out of one of the 5v sources into the Arduino. Is it possible that this might not be enough power to run two servos? I'd like to avoid the use of a regulator if possible. I am also wondering about the 12v situation, and whether or not that really would burn the chip out prematurely. Reboticon, I know you said you were down to do some experimenting on an Xbox you've got lying around. Wanna see if one of the 5v sources will power an Arduino? Here's a list of power outs on the motherboard: http://img229.imageshack.us/i/4dyu9s2jv2.png/ Let me know what you think.
Ok, I did some experimenting. Took a couple pictures, but i dropped my digital camera last week and all ihave is my TERRIBLE cell phone camera. So no complaining "youze didn't use macro mode!"
First thing, Look at the image in what I quoted. Then look at the first picture you posted of 360 internals earlier in the thread. This second picture (the one that i quoted) is the OLD style box. Notice how the 3rd floating style heat sink is not in the picture, and underneath that is the only 5v power source listed in your picture.
So here is what I did. In your first link (the fans mod) they ran extra power from disk drive with no problems, and the later style even taps into those for extra fan power. so I backprobed those pins.
Now for crap cell phone pics. What I did was I cut the end off a 9v AC/DC adapter, and spliced the positive (the one with a stripe on it usually) to the drive pin labeled 5 volt. I spliced an alligator clip to the negative and just clipped it to the case. Like this.
Then I ran the 9v end to my arduino, which is currently powering a reciever board from a toy RC car usually operating at 12v.
I have it programmed with 5 LEDs. It lights one LED depending on what direction is pressed on the controller, and the 5th LED is lit when no buttons are pressed. Here it is in 5th state (no buttons pressed)
Here it is with a directional button pressed
A couple things to remember when fiddling around in there. The console works fine with the disk drive unplugged, however you MUST have the output from 360 cable hooked up. If its component cable, you can just plug it into back of box. If its HDMI cable it will only work for 5 minutes before it goes into "limp mode" (i dont know the correct term thats what we call it on cars) unless the other end of the HDMI cable is plugged into a TV.
Hope that helps ya some.